\documentclass{article}
\usepackage{multirow}

\begin{document}

\begin{table}
  \centering
  \begin{tabular}{ccc}
    \multicolumn{2}{c}{\multirow[t]{2}{*}[-.77ex]{\Large{A}}} & B \\
    & & C \\
    D & E & F  \\
  \end{tabular}
  \caption{Bla bla}
\end{table}

\end{document}
